By the way!
Does anyone leave tips for the train attendant?

No... Because it's not fashionable and "not customary."

But they accompany us from Sochi to Moscow, mop the floors, serve tea and coffee, change the bedding, maintain order, answer stupid and repetitive questions like "how long are we stopping?" (even though the schedule is on the wall).

This, by the way, is harder than bringing 2 salads and a menu. But the attendant only gets dirty laundry and our trash, unlike the waitress who gets 5-10% of the bill "for tea" 10 times a day.

Their tea is free, people!!

Be grateful for the contribution, not just out of tradition.